1. Field of the Invention
The present invention relates to a chain saw, preferably a so-called motor saw, which is useful in sawing concrete and similar, preferably hard, materials. Such chain saws include a motor which drives an enclosed saw-chain arranged along the edge of a saw-bar, the saw-chain comprising links, of at least some of which are fitted with at least one cutter projecting from the saw-bar.
2. The Prior Art
The known motor-saws are provided with a saw-chain consisting of three types of links which are movably arranged with respect to one another by means of pins in the same way as with known roller-chains. The links consist of saw-links provided with one or several sawteeth respectively, connecting links and control links provided with a drive and control lug extending into a guide groove which extends along the edge of the saw-bar. The saw-links and connecting links are joined in pairs, parallel and next to one another, by means of pins in such a way that each pair of links consists of a saw-link and a connecting link or two connecting links. Furthermore, the pairs of links are mutually connected by the control-links so as to form a chain.
The known saw-chain has the disadvantage that, when it is used for sawing hard materials such as, e.g., concrete, abraded wear-producing material collects in the chain gaps, which causes rapid wear of the chain's gliding surfaces, both in the actual chain and within the guide groove within the bar. Also, the drive arrangement fitted to the motor of the saw and driving the chain around the bar becomes worn, owing to the action of the abraded material.